<ol>
  <li>Enter the distance of the concentric arc from the original base arc in
  the options tool bar.</li>
  <li>Enter the number of concentric arcs to create in the options
  tool bar.</li>
  <li>Click the base arc. The concentric arc(s) are created on that side on
  which the mouse cursor is located while clicking the base arc.</li>
</ol>
